The 1990 National Assessment of Educational Progress (NAEP) monitored the performance of students in American schools in the subject areas of reading, mathematics, science, and writing. The sample involved more than 146,000 public- and private-school students who were 9-, 13-, or 17-years old or in grades 4, 8, 11, or 12. The purpose of the report is to provide details on the instrument development, sample design, data collection, and data analysis procedures of the 1990 assessment. An additional sample of approximately 100,000 eighth-grade public-school students in 40 states and territories was assessed in mathematics as part of the 1990 Trial State Assessment. Part I, "The Design and Implementation of the 1990 NAEP" includes the following chapters: (1) "Overview of Part I: The Design and Implementation of the 1990 NAEP"; (2) "Developing the NAEP Objectives, Items, and Background Questions for the 1990 Assessments of Reading, Mathematics, and science"; (3) "Sample Design"; (4) "Assessment Instruments"; (5) "Field Operations and Data Collection"; (6) "Processing of Materials and Data"; (7) "Professional Scoring"; and (8) "Database Creation, Quality Control of Data Entry, and Database Products." Part II, "The Analysis of the 1990 NAEP Data" includes: "Overview of Part II: The Analysis of 1990 NAEP Data"; (10) "Weighting Procedures and Estimation of Sampling Variance"; (11) "Scaling Procedures"; (12) "Data Analysis for the Reading Assessment"; (13) "Data Analysis for the Mathematics Assessment"; (14) Data Analysis for the Science Assessment"; and (15) "Data Analysis for the Writing Assessment." Part III, "Statistical Summary of 1990 NAEP Data" includes: (16) "Statistical Summary of 1990 NAEP Data and Estimates of the Proficiencies of American Students." Eight appendixes provide additional information. Contains a glossary, 86 references cited in text, and an index. (ZWH)